Traveling grate



April 20 1926.

W. R. WOOD TRAVELING GRATE Filed August 1, 1923 Q Q x I 44ml! A TTORNE V I sieving action of Patented Apr. 20, 1926.

UNITED STATES 1,581,373 PATENT OFFI E,

WILFRED E. woon, OE LONDON, ENGLAND, AssreNon To INTERNATIONAL COMBUS- TION ENGINEERING CORPORATION, OE NEW YORK, N. Y., A CORPORATION OF DELAWARE.

TRAVELING GRATE.

To all whom it may concern:

Be it known that I, 'WILERED \Vooo, a citizen of the United States, residing at London, England, have invented certain newand useful Improvements in Traveling Grates, of which the following. is a specification.

This invention relates to improvements in traveling grates, and is in connection with the chain grate type of stoker mechanism used in furnaces or combustion chambers under boilersfor the generation of steam.

The nature, objects and advantages of my invention will. be best understood from a brief description of present practice.

Heretofore it has been largely customary to make the links of a chain grate stoker of cast iron. These links, particularly the upper faces thereof, are of substantially uniformv dimension and, for purposes of strength, have been made about from 5/ to 1" in width. As a result the gaps or spaces between ends of adjacent links of a row of links is quite large, and each gap, as wear takes place, j ectionably increasing the riddling or the grate. The links of the several rows of links constituting a chain are staggered and, to Overcome the difficulty mentioned, I am aware that it has been pro posed to provide the middle portions of the links with a projecting ledge adapted to extend partially over the gap between; adjacent ends of the links of an adjacent row. This, however, is unsatisfactory for the reason that these ledges or horns, being of necessity small and presenting sharp corners, burn off relatively quickly.

I have recently developed a link for a chain grate which is made by shearing a flat steel bar, such links being wide. This form of link has many advantages over the cast metal links described.

By my present invention I propose'to obtain certain of the advantages of the sheared links and to avoid certain of the disadvan tages of the cast links described.

More specifically stated, one of the primary objects of my invention is to provide a link which'may be cast, which will have adequate strength, and which, when assembled in .chain form, will minimize the gap between adjacent ends of links so as to reduce the rid'dling or sieving action of the chain grate.

particularly useful increases rapidly, thereby ob-' Another object is to provide a construction such that, as wear takes place, the increase in area of the riddling gap will not become objectionable.

A further object of the invention-is to provide a construction by virtue of which there is less pressureon the pins or pintles of the chain when crushing material which may lie in the joints at the time of passage around the front and back shafts.

How the foregoing, together with such other objects as may hereinafter appear, or are incident to my invention, are obtained, is illustrated in the accompanying "drawings, wherein:

Fig. 1 1s a plan view of a portion of a chain grate embodying my improvements; Fig. 2 1s a side elevation of parts shown 1n Fig. 1; Fig. 3 is a side elevation of a single link; and Figs. 4 and '5 are sections taken on the lines 4.-4: and 55, respectively, of Fig. 3. i

Referring now to the drawings, it will be seen that the chain grateA is composed of links B which are arranged in rows, thenumber of rows depending upon the width of the grate, and the ends of the links being hooked over the pintles 7. It will be understood that the chain constitutes, in effect. an

endless belt passing over a sprocket means at one end and a drum or roller at the other the grate, in its upper traverse, beingsupported on a plurality of rollers. The shaft carrying the sprocket mechanism'is driven.

The links Bare counterpart. The'middle portion of each link is widened wedge fashion. On either side of the widened middle portion is a uniform portion 9. The widened portionv tapers from the middle thereofto- Ward both ends of the link and merges in the uniform portions 9'. The end portions 10 of the link taper down from the uniform portions 9, and the taper of the middle and end portions is the same. I prefer to have the width of the top surfaces of the various portions of the link as follows In the neighborhood of for the middle portion, for the uniform portions, and for the end portions at the extremities'thereof. The lateral faces of the end portions 10 are formed with inclined surfaces, as indicated at 11 and l2.

Each uniform portion 9 has a pintlereceiving slot 13, such slots inclining downwardly and inwardly, toward the middle of the .link. The outer edge portions 13 of mouths of the slots 13 lie between vertical planes passing through the outer edge portions 13 of the pintle seats of the slots. By virtue of this slot arrangement, the links cannot come 01f the pintles; but they be readilydetached where they pass around the front 01' back shaft, in the manner disclosed in my copending application Serial No. 635,- 04e5,filed April 27, 1923.

A'djacent each pintle slot, each link has on opposite sides bosses 14 that space the links apart to secure the needed vertical air openings therebetween. Each link, in its lower face, to one side of the center, is provided with a tooth 15 and these teeth cooperate with the inclined surfaces 11 of adjacent links to receive the sprocket teeth for driving purposes.

It will be seen that by this arrangement and construction of link, the gaps 16 between ends of adjacent links of a row of links are reduced to minimum width and, therefore, minimum area, and that as wear takes place on the pintles and pintle seats, the area of such gaps, by virtue of their short length, is not objectionably increased; so that the amount of riddling or sieving is reduced'to about half what it would be when the links are made of the cast construction heretofore described. At the same time, however, the links have adequate strength and there is little 'or no liability of burning :away at the middle because there are no sharp corners. In this connection, it is to be remarked that the angles of the tapered portions are quite obtuse. Thus, the only factor that enters into consideration with relation to the riddling gaps is the wear on the pintles and pintle seats. Another advantage of the arrangement is that by virtue of the relatively small surfaces presented by the extremities of the links, any material that enters into the joints when the chain is flexed in passing around the shafts at the ends of the grate, will be crushed with minimum pressure on the .pintles. The links are detachable far more readily than any cast links heretofore employed, such cast links usually being provided with holes.

- Other advantages will occur to those skilled in the art.

lVhat I claim is:

.1. A chain. grate composed of rows of substantially aligned counterpart links, each narrowed .at the ends and wider in the middie, the narrow ends of links in one row overlapping the wider middle portions of links in an adjacent row.

2. A link for a chain grate having end portions narrower than its middle portion, with intermediate portions of substantiall uni-form, intermediate width; so that when .rows of such links are assembled with links of adjacent rows staggered and an intermediate portion of one opposite a similar portion of another, the middle of one link will lie opposite the narrow ends of adjacent links.

3. A link for a chain grate having end portions narrower than its middle portion,

4. A link for a chain grate having end portions narrower than its middle portion with portions intermediate the middle and end portions of substantially uniform intermediate width and pintle openings in said intermediate portions.

5. A link for a chain grate having both ends laterally tapered and a similarly tapered middle portion.

6. A link for a chain grate having a relatively wide middle portion laterally tapering towards opposite ends from the middle, a portion of uniform width at each end of the middle portion, and end portions laterally tapering towards the extremities of the links.

7. A link for a chain grate having a relatively wide middle portion laterally tapering towards opposite ends from the middle, a portion of uniform width at each end of the middle portion, and end portions laterally tapering towards the extremities of the links, the angle of taper being approximately the same for both middle and end portions.

8. A link for a chain grate having substantially' uniform intermediate portions, end portions joining said intermediate portions at substantially the same width and tapering laterally away from their respective junctions, and a wider middle portion tapering laterally in opposite directions and joining said intermediate portions at substantially the same width.

9. A link for a chain grate having a relatively wide middle portion laterally tapering toward opposite ends from the middle, a portion of uniform width at each end of the middle portion, and end portions laterally tapering toward the extremities of the link, the uniform portions having pintlereceiving openings.

10. A link for a chain grate having substantially uniform intermediate portions, end portions joining said intermediate portions at substantially the same width and tapering laterally away from their respective junctions, and a wider middle portion tapering laterally in opposite directions and joining said intermediate portions at substantially the same width; said uniform in- 

